International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Jun 2003
Clinical TrialSimultaneous integrated boost intensity-modulated radiotherapy for locally advanced head-and-neck squamous cell carcinomas. I: dosimetric results.
This report describes the dosimetric analyses of a Phase I/II protocol, designed to examine the capabilities of an institutionally developed intensity-modulated radiotherapy (IMRT) system with respect to dose escalation. The protocol employed stringent dosimetric guidelines in the treatment of locally advanced head-and-neck squamous cell carcinomas (HNSCC) with radiotherapy alone using IMRT and the simultaneous integrated boost (SIB) technique. ⋯ Treatment of locally advanced HNSCC using SIB-IMRT as described is feasible. Treatment planning and delivery are safer and more efficient than with conventional three-dimensional processes. Predicted dose distributions can be accurately delivered with excellent conformality using dynamic MLC. At least one of the parotid glands can be adequately spared. Patient follow-up continues and will allow eventual quantitative correlation of delivered dose distributions with clinical outcomes.
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Int. J. Radiat. Oncol. Biol. Phys. · Jun 2003
Is intraoperative nomogram-based overplanning of prostate implants necessary?
Several investigators have described intraoperative planning of prostate implants based on a nomogram. The aim of this work was to investigate the adequacy of the nomogram in predicting the total activity necessary for optimal dosimetry. ⋯ The doses evaluated at CT1 represent an underestimate, whereas those obtained at CT2 represent an overestimate of the actual delivered protracted permanent implant dose. Based on these results and consideration of the dynamic nature of the dose distribution, target coverage obtained with intraoperative planning using the nomogram predicted activity is consistent with published guidelines for a quality implant and critical structure doses are within tolerance.
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Int. J. Radiat. Oncol. Biol. Phys. · Jun 2003
Experience of ultrasound-based daily prostate localization.
The NOMOS (Sewickley, PA) B-mode Acquisition and Targeting System (BAT) ultrasound system provides a rapid means of correcting for interfraction prostate positional variation. In this investigation, we report our experience on the clinical issues relevant to the daily use of the BAT system and the analysis of combined setup error and organ motion for 3509 BAT alignment procedures in 147 consecutive patients treated with IMRT for prostate cancer. ⋯ The quality of the daily ultrasound images was deemed acceptable in 95%. Major alignment errors by therapists were only 3%. The BAT system is clinically effective and feasible in a matter of 5 min. Although the accuracy of the BAT was not addressed in this investigation, we found a significant percentage of large shifts being made from the initial alignment position.
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Int. J. Radiat. Oncol. Biol. Phys. · Jun 2003
Significance of dose in postoperative radiotherapy for soft tissue sarcoma.
For soft tissue sarcoma, adjuvant postoperative radiotherapy improves the local control rate over surgery alone. However, the issue of a dose-control relationship is controversial and was addressed in this study. ⋯ After gross total resection, soft tissue sarcoma with features predictive of a higher than average local recurrence rate benefited from doses of 64-68 Gy compared with 60 Gy.
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Int. J. Radiat. Oncol. Biol. Phys. · Jun 2003
Multicenter Study Clinical TrialMature survival results with preoperative cisplatin, protracted infusion 5-fluorouracil, and 44-Gy radiotherapy for esophageal cancer.
To assess the long-term survival results after cisplatin, protracted infusion 5-fluorouracil, and concurrent radiotherapy (RT) followed by surgical resection of esophageal cancer. ⋯ The promising 5-year survival results and low rate of late cancer-related deaths suggest that these regimens of intensive neoadjuvant therapy may improve the overall cure rate. The pathologic stage after neoadjuvant therapy is an important predictor of survival and may be useful in selecting patients for novel adjuvant therapies. Isolated local failure is uncommon, indicating that efforts to improve the therapeutic outcome should focus on optimizing systemic therapy rather than intensifying the RT. Additional randomized data are needed to assess the benefits of this therapeutic approach fully.